Abrasive coating including metal matrix and ceramic particles

ABSTRACT

A system may include a powder source; a powder delivery device; an energy delivery device; and a computing device. The computing device may be configured to: control the powder source to deliver metal powder to the powder delivery device; control the powder delivery device to deliver the metal powder to a surface of an abrasive coating; and control the energy delivery device to deliver energy to at least one of the abrasive coating or the metal powder to cause the metal powder to be joined to the abrasive coating.

This application is a divisional filing of U.S. patent application Ser.No. 16/717,895, filed 17 Dec. 2019, the entire contents of which isincorporated herein by reference.

TECHNICAL FIELD

The disclosure relates to abrasive coatings.

BACKGROUND

Systems that use compression of fluids, such as pumps, compressors,turbines, and the like use seals between rotating and static componentsto improve their functioning, such as efficiency. In low temperatureapplications, the seals may be formed from materials such as rubber orpolymers. In high temperature systems, such as gas turbine engines,rotating components may include an abrasive coating on tips or end wallsof the rotating components and adjacent static components may includeabradable coatings. During use, the abrasive coating may wear a grooveinto the abradable coating to form a seal while reducing orsubstantially preventing damage to the rotating component.

SUMMARY

In some examples, the disclosure describes a method that includescontrolling, by a computing device, a powder source to deliver metalpowder to a powder delivery device; controlling, by the computingdevice, the powder delivery device to deliver the metal powder to asurface of an abrasive coating; and controlling, by the computingdevice, an energy delivery device to deliver energy to at least one ofthe abrasive coating or the metal powder to cause the metal powder to bejoined to the abrasive coating.

In some examples, the disclosure describes a system that includes apowder source; a powder delivery device; an energy delivery device; anda computing device. The computing device is configured to: control thepowder source to deliver metal powder to the powder delivery device;control the powder delivery device to deliver the metal powder to asurface of an abrasive coating; and control the energy delivery deviceto deliver energy to at least one of the abrasive coating or the metalpowder to cause the metal powder to be joined to the abrasive coating.

In some examples, the disclosure describes a computer-readable storagedevice comprising instructions that, when executed, configure one ormore processors of a computing device to: control a powder source todeliver metal powder to a powder delivery device; control the powderdelivery device to deliver the metal powder to a surface of an abrasivecoating; and control an energy delivery device to deliver energy to atleast one of the abrasive coating or the metal powder to cause the metalpowder to be joined to the abrasive coating.

In some examples, the disclosure describes a method includingcontrolling, by a computing device, an energy delivery device to deliverenergy to an abrasive coating, wherein the abrasive coating comprises ametal matrix and abrasive particles at least partially encapsulated bythe metal matrix; and controlling, by the computing device, the energydelivery device to scan the energy across a surface of the abrasivecoating and form a series of softened or melted portions of the metalmatrix.

In some examples, the disclosure is directed to a system that includesan energy delivery device; and a computing device, wherein the computingdevice is configured to: control the energy delivery device to deliverenergy to an abrasive coating, wherein the abrasive coating comprises ametal matrix and abrasive particles at least partially encapsulated bythe metal matrix; and control the energy delivery device to scan theenergy across a surface of the abrasive coating and form a series ofsoftened or melted portions of the metal matrix.

In some examples, the disclosure describes a computer-readable storagedevice comprising instructions that, when executed, configure one ormore processors of a computing device to: control an energy deliverydevice to deliver energy to an abrasive coating, wherein the abrasivecoating comprises a metal matrix and abrasive particles at leastpartially encapsulated by the metal matrix; and control the energydelivery device to scan the energy across a surface of the abrasivecoating and form a series of softened or melted portions of the metalmatrix.

The details of one or more examples are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual block diagram illustrating an example system forprocessing an abrasive coating after deposition of the abrasive coatingto improve properties of the abrasive coating.

FIG. 2 is a flow diagram illustrating an example technique forprocessing an abrasive coating after deposition of the abrasive coatingto improve properties of the abrasive coating.

FIG. 3 is a conceptual diagram illustrating an example article includingan abrasive coating.

FIG. 4 is a flow diagram illustrating an example technique forprocessing an abrasive coating after deposition of the abrasive coatingto improve properties of the abrasive coating.

FIG. 5 is a flow diagram illustrating an example technique forprocessing forming an abrasive coating using directed energy depositionmaterial addition an abrasive coating after deposition of the abrasivecoating to improve properties of the abrasive coating.

FIG. 6 is a conceptual diagram illustrating a system that includes arotating component, an abrasive coating on the rotating component, and astationary component adjacent the rotating component.

DETAILED DESCRIPTION

The disclosure generally describes techniques for forming abrasivecoatings that include a metal matrix and ceramic abrasive particles.Some such coatings have been formed using electroplating. However,electroplating limits the alloys that can be used to alloys compatiblewith electroplating processes. Many of these alloys are relatively lowtemperature alloys, which limits the systems in which the abrasivecoatings can be used.

Other abrasive coatings that include a metal matrix and ceramic abrasiveparticles have been deposited using additive manufacturing techniques,such as blown powder directed energy deposition. While blown powderdirected energy deposition may allow use of alloys that are notcompatible with electroplating, abrasive coatings deposited using blownpowder directed energy deposition may result in abrasive coatings thatare more uneven (e.g., have a higher surface roughness) than abrasivecoatings deposited using electroplating. The higher surface roughnessmay reduce effectiveness as an abrasive coating, as the seal formed bythe abrasive coating wearing into an adjacent abradable coating may beless complete. Additionally, or alternatively, the abrasive particlesmay be less embedded in the metal matrix, leading to a greater chance ofthe abrasive particles becoming dislodged from the metal matrix and ashorter lifetime of the abrasive coating.

In accordance with some examples of this disclosure, an abrasive coatingmay be subjected to additional processing after initial deposition toimprove properties of the abrasive coating. In some examples, after theabrasive coating is formed on a substrate, directed energy depositionmay be used to deposit additional metal matrix material, which furtherencapsulates the abrasive particles in the abrasive coating, reducessurface roughness, or both. In other examples, after the abrasivecoating is formed on a substrate, an energy source, such as a laser or aplasma may be used to soften or melt the metal matrix. The softening ormelting of the metal matrix may allow surface tension/surface energy tocause the metal matrix to flow around the abrasive particles and makethe height and surface roughness of the abrasive coating more uniform.

In some examples, the additional powder deposition technique and thesoftening or melting technique may be used together, in either order.For example, after the abrasive coating is formed on a substrate,directed energy deposition may be used to deposit additional metalmatrix material. The abrasive coating including the additional metalmatrix material then may be softened or melted using a laser or a plasmaenergy source. As another example, after the abrasive coating is formedon a substrate, the abrasive coating may be softened or melted using alaser or a plasma energy source, then directed energy deposition may beused to deposit additional metal matrix material. In either case, thecombination of the two technique may be used to provide lower surfaceroughness and more uniform height to the abrasive coating, whileallowing use of high temperature metal matrices, such as nickel- orcobalt-based superalloys.

FIG. 1 is a conceptual block diagram illustrating an example system 10for processing an abrasive coating 22 after deposition to improveproperties of abrasive coating 22. In the example illustrated in FIG. 1, system 10 includes a computing device 12, a powder delivery device 14,an energy delivery device 16, a stage 18, a first material source (FMS)24, and an optional second material source (SMS) 24. Computing device 12is communicatively connected to powder delivery device 14, energydelivery device 16, and stage 18.

Abrasive coating 22 is on a surface or surfaces of component 20.Component 20 may be any component of a mechanical system in which a sealis to be made between component 20 and an adjacent component. Forexample, component 20 may be a rotating component in a mechanicalsystem, which is adjacent to a stationary component or acounter-rotating component. For instance, component 20 may be a knifeseal, a blade (such as a gas turbine engine blade), a wall of a scrollcompressor or other compressor or pump, or the like. The adjacentcomponent may include a stator, a runner, a blade track or blade shroud,or the like. In some examples, component 20 is formed from a metal or analloy, such as a steel (e.g., stainless steel), a nickel-based alloy, acobalt-based alloy, a titanium-based alloy, or the like.

Abrasive coating 22 may include a metal matrix and abrasive particles.The metal matrix may include any suitable metal or alloy. In someexamples, the metal matrix includes a composition that is the same asthe composition of component 20. In other examples, the metal matrixincludes a composition that is different from the composition ofcomponent 20.

In some examples, the metal matrix may include a high-performance metalor alloy, such as a steel (e.g., stainless steel), a nickel-based alloy,a cobalt-based alloy, a titanium-based alloy, or the like. In someexamples, the metal matrix may include a nickel-based, iron-based, ortitanium-based alloy that includes one or more alloying additions suchas one or more of Mn, Mg, Cr, Si, Co, W, Ta, Al, Ti, Hf, Re, Mo, Ni, Fe,B, Nb, V, C, and Y. In some examples, the metal matrix may include apolycrystalline nickel-based superalloy or a polycrystallinecobalt-based superalloy, such as an alloy including NiCrAlY orCoNiCrAlY. For example, the metal matrix may include an alloy thatincludes 9 to 10.0 wt. % W, 9 to 10.0 wt. % Co, 8 to 8.5 wt. % Cr, 5.4to 5.7 wt. % Al, about 3.0 wt. % Ta, about 1.0 wt. % Ti, about 0.7 wt. %Mo, about 0.5 wt. % Fe, about 0.015 wt. % B, and balance Ni, availableunder the trade designation MAR-M 247™, from various suppliers. In someexamples, the metal matrix may include an alloy that includes 22.5 to24.35 wt. % Cr, 9 to 11 wt. % Ni, 6.5 to 7.5 wt. % W, less than about0.55 to 0.65 wt. % of C, 3 to 4 wt. % Ta, and balance Co, availableunder the trade designation MAR-M 509™, from various suppliers. In someexamples, the metal matrix may include an alloy that includes 19 to 21wt. % Cr, 9 to 11 wt. % Ni, 14 to 16 wt. % W, about 3 wt. % Fe, 1 to 2wt. % Mn, and balance Co, available under the trade designation HAYNES®25 alloy from Haynes International, Kokomo, Indiana. In some examples, ametal matrix may include a chemically modified version of MAR-M 247™that includes less than 0.3 wt. % C, between 0.05 and 4 wt. % Hf, lessthan 8 wt. % Re, less than 8 wt. % Ru, between 0.5 and 25 wt. % Co,between 0.0001 and 0.3 wt. % B, between 1 and 20 wt. % Al, between 0.5and 30 wt. % Cr, less than 1 wt. % Mn, between 0.01 and 10 wt. % Mo,between 0.1 and 20. % Ta, and between 0.01 and 10 wt. % Ti. In someexamples, the metal matrix may include a nickel based alloy availableunder the trade designation IN-738 or INCONEL® 738, or a version of thatalloy, IN-738 LC, available from Special Metals Corporation, NewHartford, New York, or a chemically modified version of IN-738 thatincludes less than 0.3 wt. % C, between 0.05 and 7 wt. % Nb, less than 8wt. % Re, less than 8 wt. % Ru, between 0.5 and 25 wt. % Co, between0.0001 and 0.3 wt. % B, between 1 and 20 wt. % Al, between 0.5 and 30wt. % Cr, less than 1 wt. % Mn, between 0.01 and 10 wt. % Mo, between0.1 and 20 wt. % Ta, between 0.01 and 10 wt. % Ti, and a balance Ni. Insome examples, the metal matrix may include an alloy that includes 5.5to 6.5 wt. % Al, 13 to 15 wt. % Cr, less than 0.2 wt. % C, 2.5 to 5.5wt. % Mo, Ti, Nb, Zr, Ta, B, and balance Ni, available under the tradedesignation IN-713 or INCONEL® 713 from Special Metals Corporation, NewHartford, New York.

In some examples, the metal matrix may include a refractory metal or arefractory metal alloy, such as molybdenum or a molybdenum alloy (suchas a titanium-zirconium-molybdenum or a molybdenum-tungsten alloy),tungsten or a tungsten alloy (such as a tungsten-rhenium alloy or analloy of tungsten and nickel and iron or nickel and copper), niobium ora niobium alloy (such as a niobium-hafnium-titanium alloy), tantalum ora tantalum alloy, rhenium or a rhenium alloy, or combinations thereof.

The abrasive particles may include a ceramic, such as a metal nitride, ametal carbide, a metal oxide, or the like. For example, the abrasiveparticles may include cubic boron nitride, aluminum oxide, zirconiumoxide, silicon carbide, silicon nitride, titanium nitride, zirconiumnitride, tantalum nitride, hafnium nitride, or the like.

In some examples, stage 18 is movable relative to energy delivery device16 and/or energy delivery device 16 is movable relative to stage 18.Similarly, stage 18 may be movable relative to powder delivery device 14and/or powder delivery device 14 may be movable relative to stage 18.For example, stage 18 may be translatable along at least one axis (e.g.,the z-axis shown for purposes of illustration in FIG. 1 ) to positioncomponent 20 relative to energy delivery device 16 and/or powderdelivery device 14. Similarly, energy delivery device 16 and/or powderdelivery device 14 may be translatable and/or rotatable along at leastone axis (e.g., translatable along the x- and y-axes shown in FIG. 1 )to position energy delivery device 16 and/or powder delivery device 14,respectively, relative to component 20. Stage 18 may be configured toselectively position and restrain component 20 in place relative tostage 18 during manufacturing and/or processing of abrasive coating 22.

Powder delivery device 14 may be configured to deliver material to thelocation of abrasive coating 22. In some examples, the material may besupplied by powder delivery device 14 in powder form, e.g., as a metalpowder, an abrasive powder, or a mixture of metal powder and abrasivepowder.

In some examples, system 10 may be a blown powder directed energydeposition system. In some such systems, powder delivery device 14 maydeliver the powder adjacent to the surface of component 20 and/orabrasive coating 22 by blowing the powder in a powder stream adjacent tothe surface, e.g., as a mixture of the powder with a gas carrier. Insome examples, powder delivery device 14 thus may be fluidically coupledto a material source (such as first material source 24) that provides afluidized powder (e.g., a powder carried in a gas), and powder deliverydevice 14 may include at least one nozzle or other mechanism fordirecting the powder stream to a particular location adjacent component20. In some examples, powder delivery device 14 may be mechanicallycoupled or attached to energy delivery device 16 to facilitate deliveryof powder and energy for heating the powder or a location of component20 and/or abrasive coating 22 at or near where the powder is delivered.

In other examples, system 10 may be a powder bed directed energydeposition system. In some such examples, powder delivery device 14 maydeliver the powder adjacent to the surface of component 20 and/orabrasive coating 22 by spreading the powder on the surface of component20 and/or abrasive coating 22, such that the powder rests on the surfaceprior to the powder, component 20 and/or abrasive coating 22 beingheated. In some examples of a powder bed additive manufacturing system,powder delivery device 14 may include a device that spreads the powderor can otherwise manipulate the powder to move the powder within system10.

In some examples, powder delivery device 14 may be coupled to a singlematerial source, e.g., first material source 24. First material source24 may include a source of a mixture of the metal powder and theabrasive powder. Thus, to deposit abrasive coating 22, computing device12 may be configured to control first material source 24 to deliver themixture of the metal powder and the abrasive powder to powder deliverydevice 14, which computing device 12 controls to deliver the mixture ofthe metal powder and the abrasive powder to component 20 to depositabrasive coating 22.

In some examples, powder delivery device 14 may couple to two materialsources. In some implementations, first material source 24 may include asource of metal powder and second material source 26 may include asource of abrasive powder. Thus, to deposit abrasive coating 22,computing device 12 may be configured to control first material source24 to deliver the metal powder and control second material source 26 todeliver the abrasive powder to powder delivery device 14, whichcomputing device 12 controls to deliver the mixture of the metal powderand the abrasive powder to component 20 to deposit abrasive coating 22.

In other implementations, first material source 24 may include a sourceof metal powder mixed with abrasive powder and second material source 26may include a source of metal powder. Thus, to deposit abrasive coating22, computing device 12 may be configured to control first materialsource 24 to deliver the mixture of the metal powder and the abrasivepowder to powder delivery device 14, which computing device 12 controlsto deliver the mixture of the metal powder and the abrasive powder tocomponent 20 to deposit abrasive coating 22. Computing device may beconfigured to control second material source 26 to deliver the metalpowder to powder delivery device 14 during further processing ofabrasive coating 22 to deposit additional metal matrix.

The metal powder may include any suitable metal or alloy configured toform a metal matrix in which abrasive particles are at least partiallyencapsulated. For example, the metal powder may include any of themetals or alloys described above with respect to the metal matrix.

The abrasive powder may include ceramic particles, such as a metalnitride, a metal carbide, a metal oxide, or the like. For example, theabrasive powder may include boron nitride, aluminum oxide, zirconiumoxide, silicon carbide, silicon nitride, titanium nitride, zirconiumnitride, tantalum nitride, hafnium nitride, or the like.

Energy delivery device 16 may include an energy source, such as a lasersource, an electron beam source, plasma source, or another source ofenergy that may be absorbed by component 20, the metal powder, and/orthe metal matrix of abrasive coating 22. Example laser sources include aCO laser, a CO₂ laser, a Nd:YAG laser, or the like. In some examples,the energy source may be selected to provide energy with a predeterminedwavelength or wavelength spectrum that may be absorbed by component 20,the metal powder, and/or the metal matrix of abrasive coating 22.Similarly, the energy source may be selected to provide a powder andenergy density (e.g., energy per unit focal volume) sufficient to softenand/or melt component 20, the metal powder and/or the metal matrix ofabrasive coating 22.

In some examples, energy delivery device 16 also includes an energydelivery head, which is operatively connected to the energy source. Theenergy delivery head may aim or direct the energy toward predeterminedpositions adjacent to and/or within a volume of component 20 and/orabrasive coating 22 during the processing technique. As described above,in some examples, the energy delivery head may be movable in at leastone dimension (e.g., translatable and/or rotatable) under control ofcomputing device 12 to direct the energy toward a selected locationadjacent to d/or within a volume of component 20 and/or abrasive coating22.

Computing device 12 may include, for example, a desktop computer, alaptop computer, a workstation, a server, a mainframe, a cloud computingsystem, or the like. Computing device 12 is configured to controloperation of system 10, including, for example, powder delivery device14, energy delivery device 16, stage 18, first material source 24,and/or second material source 26. Computing device 12 may becommunicatively coupled to powder delivery device 14, energy deliverydevice 16, stage 18, first material source 24, and/or second materialsource 26 using respective communication connections. In some examples,the communication connections may include network links, such asEthernet, ATM, or other network connections. Such connections may bewireless and/or wired connections. In other examples, the communicationconnections may include other types of device connections, such as USB,IEEE 1394, or the like. In some examples, computing device 12 mayinclude control circuitry, such as one or more processors, including oneor more microprocessors, digital signal processors (DSPs), applicationspecific integrated circuits (ASICs), field programmable gate arrays(FPGAs), or any other equivalent integrated or discrete logic circuitry,as well as any combinations of such components. The term “processor” or“processing circuitry” may generally refer to any of the foregoing logiccircuitry, alone or in combination with other logic circuitry, or anyother equivalent circuitry. A control unit including hardware may alsoperform one or more of the techniques of this disclosure.

Computing device 12 may be configured to control operation of powderdelivery device 14, energy delivery device 16, and/or stage 18 toposition component 20 and/or abrasive coating 22 relative to powderdelivery device 14 and/or energy delivery device 16. For example, asdescribed above, computing device 12 may control stage 18, powderdelivery device 14, and/or energy delivery device 16 to translate and/orrotate along at least one axis to position component 20 and/or abrasivecoating 22 relative to powder delivery device 14 and/or energy deliverydevice 16. Positioning component 20 and/or abrasive coating 22 relativeto powder delivery device 14 and/or energy delivery device 16 mayinclude positioning a predetermined surface (e.g., a surface to whichmaterial is to be added, a surface which is to be re-melted, or thelike) of component 20 and/or abrasive coating 22 in a predeterminedorientation relative to powder delivery device 14 and/or energy deliverydevice 16.

In accordance with some examples of this disclosure, computing device 12may be configured to control system 10 to subject abrasive coating 22 toadditional processing after initial deposition of abrasive coating 22 toimprove properties of abrasive coating 22. In some examples, afterabrasive coating 22 is formed on component 20 (e.g., a glade tip, knifetip, or the like), computing device 12 may be configured to controlpowder delivery device 14 and energy delivery device 16 to performdirected energy deposition to deposit additional metal matrix material,which further encapsulates the abrasive particles in the abrasivecoating, reduces surface roughness, or both. During the deposition ofadditional metal matrix material, computing device 12 may control amaterial source (e.g., first material source 24 or second materialsource 26, depending on the powder that the material source provides) toprovide metal powder to powder delivery device 14. Computing device 12also may control powder delivery device 14 to provide the metal powderto a surface of abrasive coating 22 and control energy delivery device16 to delivery energy at or near a surface of abrasive coating 22 tosoften or melt the metal powder and/or the metal matrix near thelocation at which powder delivery device 14 is delivering the metalpowder to cause the metal powder to be added to the metal matrix. Thismay build up metal matrix around the abrasive particles, increasingencapsulation of the abrasive particles in the metal matrix and reducingsurface roughness of abrasive coating 22. This may lead to greaterdurability for abrasive coating 22 (due to reduced loss of abrasiveparticles during abrasion of an adjacent surface), reduced surfaceroughness (which may result in a better seal between component 20 and anadjacent component), or the like.

In other examples of the disclosure, after abrasive coating 22 is formedon component 20, computing device 12 may control energy delivery device16 to soften or melt the metal matrix of abrasive coating 22, withoutdelivery of additional metal matrix. The softening or melting of themetal matrix of abrasive coating 22 may allow surface tension/surfaceenergy to cause the metal matrix to flow around the abrasive particlesand make the height and surface roughness of abrasive coating 22 moreuniform.

In some examples, computing device 12 may be configured to perform boththe additional powder deposition technique and the softening or meltingtechnique, in either order. In either order, the combination of the twotechnique may be used to provide lower surface roughness and moreuniform height to abrasive coating 22, while allowing use of hightemperature metal matrices, such as nickel- or cobalt-based superalloys.

An example technique that may be implemented by system 10 will bedescribed with concurrent reference to FIG. 2 . FIG. 2 is a flow diagramillustrating an example technique for processing an abrasive coatingafter deposition of the abrasive coating to improve properties of theabrasive coating. Although the technique of FIG. 2 is described withrespect to system 10 of FIG. 1 and component 20 of FIG. 3 , in otherexamples, the technique of FIG. 2 may be performed by other systems,such as systems including fewer or more components than thoseillustrated in FIG. 1 . Similarly, system 10 may be used to performedother techniques (e.g., the technique illustrated in FIGS. 4 and 5 ).

The technique of FIG. 2 includes controlling, by computing device 12, amaterial source (e.g., second material source 26) to deliver metalpowder to powder delivery device 14 (30). For example, computing device12 may be configured to control at least one of a valve, a pump, or thelike to enable flow of fluidized powder with a selected flow rate ofmetal powder from second material source 26 to powder delivery device14. As described above, the metal powder may include any suitable metalfor forming a metal matrix of an abrasive coating. In the example ofFIG. 2 , abrasive particles may be omitted, as an abrasive coating isalready present on the surface of the article being processed.

The technique of FIG. 2 also includes controlling, by computing device12, powder delivery device 14 to deliver the metal powder to a surface44 of abrasive coating 22 (32; see FIG. 3 ). Computing device 12 maycontrol powder delivery device 14 to move relative to component 20 sothat metal powder is delivered to selected location(s) of the surface 44of abrasive coating 22. Additionally, computing device 12 may controlstage 18 to position component 20 relative to powder delivery device 14.

Concurrently, the technique of FIG. 2 further includes controlling, bycomputing device 12, energy delivery device 16 to deliver energy tometal matrix 40 and/or the metal powder to cause the metal powder to beadded to metal matrix 40 at surface 44 (34). Computing device 12 maycontrol the power, spot size, scanning rate, frequency, pulse duration,and the like of the energy output by energy delivery device 16 tocontrol the energy delivered to metal matrix 40 and/or the metal powderso that the metal powder is joined to metal matrix 40. For example,computing device 12 may control the power, spot size, scanning rate,frequency, pulse duration, and the like of the energy output by energydelivery device 16 to cause the energy to melt portions of metal matrix40 to form a melt pool, to which the metal power is added upon the metalpowder impacting the melt pool. For instance, computing device 12 may beconfigured to control operation and movement of powder delivery device14, energy delivery device 16, stage 18, or both, based on a computeraided manufacturing or computer aided design (CAM/CAD) file. The CAM/CADfile may define one or more operating parameters of powder deliverydevice 14, energy delivery device 16 and/or stage 18 such as, forexample, the powder flow rate (e.g., mass flow rate, volumetric flowrate, or the like) of metal powder delivered by powder delivery device14; the tool path (e.g., scanning pattern), scanning velocity, and othermovement parameters of powder delivery device 14; power, spot size,frequency, pulse duration, and the like of the energy output by energydelivery device 16; the tool path (e.g., scanning pattern), scanningvelocity, and other movement parameters of energy delivery device 16;the movement parameters of stage 18; or the like.

Computing device 12 may control energy delivery device 16 to move theenergy across surface 40 of abrasive coating 22 in concert withcontrolling powder delivery device 14 such that metal powder is added atlocations across surface 40.

In this way, computing device 12 may be configured to control system 10to add additional metal matrix 40 to an already-present abrasive coating22. As described above, during initial formation of abrasive coating 22,abrasive particles 44 may tend to project from metal matrix 40 asabrasive particles 44 may be less dense than metal matrix 40 (and thusbuoyant in the melt form of metal matrix 40). By further processingabrasive coating 22 by depositing addition metal matrix withoutadditional abrasive particles, the additional metal matrix 40 mayfurther encapsulate abrasive particles 44 in abrasive coating 22. Thismay reduce surface roughness of abrasive coating 22, improveincorporation of abrasive particles 44 in abrasive coating 22 such thatabrasive particles 44 are less likely to be removed from abrasivecoating 22 due to contact with an adjacent abradable coating, or both.Reduced surface roughness may improve a seal between a rotatingcomponent that includes multiple rotating elements and an adjacentstator or sealing component.

In some examples, further processing of abrasive coating 22 may omit anyadditional material delivery. FIG. 4 is a flow diagram illustrating anexample technique for processing an abrasive coating after deposition ofthe abrasive coating to improve properties of the abrasive coating.Although the technique of FIG. 4 is described with respect to system 10of FIG. 1 and component 20 of FIG. 3 , in other examples, the techniqueof FIG. 4 may be performed by other systems, such as systems includingfewer or more components than those illustrated in FIG. 1 . Similarly,system 10 may be used to performed other techniques (e.g., the techniqueillustrated in FIGS. 2 and 5 ).

During the technique of FIG. 4 , system 10 may delivery no additionalmaterial to abrasive coating 22. Instead, system 10 may use energydelivery device 16 to soften or re-melt one or more portions of metalmatrix 40 to allow metal matrix 40 to flow and reduce surface roughnessof abrasive coating 22.

The technique of FIG. 4 includes controlling, by computing device 12,energy delivery device 16 to delivery energy to metal matrix 40 tosoften or melt portions of metal matrix 40 (52). Computing device 12 maycontrol the power, spot size, scanning rate, frequency, pulse duration,and the like of the energy output by energy delivery device 16 tocontrol the energy delivered to metal matrix 40 such that portions ofmetal matrix 40 absorb sufficient energy to soften or melt. The energydelivered to any selected portion may be selected so that softening ormelting is relatively localized, e.g., so that abrasive particles 42 donot have sufficient mobility to flow from abrasive coating 22 and/ormetal matrix 40 does not flow from its position on component 20. Duringthis process, in systems that include powder delivery device 14,computing device 12 may be configured to control powder delivery device14 to not deliver powder to surface 44, or computing device 12 may beconfigured to not cause powder delivery device 14 to deliver powder tosurface 44.

Computing device 12 also may control energy delivery device 16 and/orstage 18 to move energy delivery device 16 relative to abrasive coating22 (54). More particularly, computing device 12 may control energydelivery device 16 and/or stage to move the energy (e.g., focal spot ofan energy beam, central portion of a plasma plume, or the like) relativeto surface 44 of abrasive coating 22. Computing device 12 may controlenergy delivery device 16 and/or stage 18 to move in a selected patternand rate to move the energy (e.g., focal spot of an energy beam, centralportion of a plasma plume, or the like) relative to surface 44 ofabrasive coating 22 to expose portions of abrasive coating 22 to aselected power and energy density to cause the selected softening and/ormelting of metal matrix 40.

For example, computing device 12 may be configured to control operationand movement of energy delivery device 16, stage 18, or both, based on acomputer aided manufacturing or computer aided design (CAM/CAD) file.The CAM/CAD file may define one or more operating parameters of energydelivery device 16 and/or stage 18 such as, for example, power, spotsize, frequency, pulse duration, and the like of the energy output byenergy delivery device 16; the tool path (e.g., scanning pattern),scanning velocity, and other movement parameters of energy deliverydevice 16; the movement parameters of stage 18; or the like.

In this way, system 10 may be used to process an abrasive coating usingenergy delivery to soften or remelt metal matrix 40 after deposition ofabrasive coating 22. The softening or melting of metal matrix 40 mayallow surface tension/surface energy to cause metal matrix 40 to flowaround abrasive particles 42 and make the height and surface roughnessof abrasive coating 22 more uniform. This may reduce surface roughnessof abrasive coating 22, improve incorporation of abrasive particles 44in abrasive coating 22 such that abrasive particles 44 are less likelyto be removed from abrasive coating 22 due to contact with an adjacentabradable coating, or both. Reduced surface roughness may improve a sealbetween a rotating component that includes multiple rotating elementsand an adjacent stator or sealing component.

In some examples, the techniques of FIG. 2 and FIG. 4 may be usedtogether, along with initial deposition of an abrasive coating, to forma finished abrasive coating. FIG. 5 is a flow diagram illustrating atechnique for forming an abrasive coating using directed energydeposition material addition and post-processing the abrasive coating toimprove properties of the abrasive coating. Although the technique ofFIG. 5 is described with respect to system 10 of FIG. 1 and component 20of FIG. 3 , in other examples, the technique of FIG. 5 may be performedby other systems, such as systems including fewer or more componentsthan those illustrated in FIG. 1 . Similarly, system 10 may be used toperformed other techniques (e.g., the technique illustrated in FIGS. 2and 4 ).

The technique of FIG. 5 includes controlling, by computing device 12,one or more material sources to deliver metal powder and abrasiveparticles to powder delivery device 14 (60). As described above withreference to FIG. 1 , in some examples a single material source (e.g.,first material source 24) is configured to provide a mixture of metalpowder and abrasive particles. In other examples, a first materialsource 24 is configured to provide metal powder and second materialsource is configured to provide abrasive particles. Thus, computingdevice 12 may control one or more materials sources to cause the one ormore material sources to delivery metal powder and abrasive particles topowder delivery device 14 (60).

Computing device 12 may control the one or more material sources todeliver metal powder and abrasive particles to powder delivery device 14in a selected ratio to result in a selected concentration of abrasivepowder 42 in the metal matrix 40 of abrasive coating 22. For example,computing device 12 may control opening and closing of one or morevalves or other flow control devices to control the flow rate offluidized powder from the one or more material sources to powderdelivery device 42.

Computing device 12 also may control powder delivery device 14 todeliver the mixture of metal powder and abrasive particles to thesurface of component 20 and/or abrasive coating 22 (62). Computingdevice 12 may control powder delivery device 14 to move relative tocomponent 20 so that metal powder and abrasive particles are deliveredto selected location(s) of the surface on which abrasive coating 22 isto be formed. Additionally, computing device 12 may control stage 18 toposition component 20 relative to powder delivery device 14.

Concurrently, the technique of FIG. 5 further includes controlling, bycomputing device 12, energy delivery device 16 to deliver energy to asurface of component 20, metal matrix 40 and/or the metal powder tocause the metal powder and abrasive particles to be joined to component20 to form abrasive coating 22 (64). Computing device 12 may control thepower, spot size, scanning rate, frequency, pulse duration, and the likeof the energy output by energy delivery device 16 to control the energydelivered to metal matrix 40 and/or the metal powder so that the metalpowder is joined to metal matrix 40, resulting in the abrasive particlesbeing incorporated in abrasive coating 22. For example, computing device12 may control the power, spot size, scanning rate, frequency, pulseduration, and the like of the energy output by energy delivery device 16to cause the energy to melt portions of component 20 and/or metal matrix40 to form a melt pool, to which the metal power is added upon the metalpowder impacting the melt pool and which abrasive particles impact andare incorporated. For instance, computing device 12 may be configured tocontrol operation and movement of powder delivery device 14, energydelivery device 16, stage 18, or both, based on a computer aidedmanufacturing or computer aided design (CAM/CAD) file. The CAM/CAD filemay define one or more operating parameters of powder delivery device14, energy delivery device 16 and/or stage 18 such as, for example, thepowder flow rate (e.g., mass flow rate, volumetric flow rate, or thelike) of metal powder and abrasive particles delivered by powderdelivery device 14; the tool path (e.g., scanning pattern), scanningvelocity, and other movement parameters of powder delivery device 14;power, spot size, frequency, pulse duration, and the like of the energyoutput by energy delivery device 16; the tool path (e.g., scanningpattern), scanning velocity, and other movement parameters of energydelivery device 16; the movement parameters of stage 18; or the like.

Computing device 12 may control energy delivery device 16 to move theenergy across surface 40 of abrasive coating 22 in concert withcontrolling powder delivery device 14 such that metal powder andabrasive particles are added at locations across a surface of component20 to form abrasive coating 22.

Computing device 12 may continue controlling powder source(s) (60),controlling powder delivery device 14 (62), and controlling energydelivery device 16 (64) until sufficient material (metal powder andabrasive particles) has been deposited to form abrasive coating 22. Assuch, computing device may control powder delivery device 14 and energydelivery device 16 to cause the powder stream and energy to follow atool path that defines a pattern (e.g., of adjacent rows) along thesurface of component 20, then control powder delivery device 14 andenergy delivery device 16 to cause the powder stream and energy tofollow a tool path that defines a pattern (e.g., of adjacent rows) alonga surface of the previously deposited layer until a desired thickness ofmaterial (metal power and abrasive particles) has been deposited oncomponent 20 to form abrasive coating 22.

Once system 10 has formed abrasive coating 22, system 10 may be used topost-process abrasive coating 22 to improve properties (e.g., surfaceroughness, incorporation of abrasive particles, or both) using thetechniques of FIGS. 2 and 4 . Although FIG. 5 illustrates the techniqueof FIG. 2 being performed before the technique of FIG. 4 , in otherexamples, the technique of FIG. 4 may be performed before the techniqueof FIG. 2 . In the example of FIG. 5 , computing device 12 may controlone or more a powder source to deliver metal powder to powder deliverydevice 14 (30), control powder delivery device to deliver the metalpowder to surface 44 of abrasive coating 22 (32), and, concurrently,control energy delivery device 16 to deliver energy to metal matrix 40and/or the metal powder to cause the metal powder to be added to metalmatrix 40 (34). Computing device 12 also may control energy deliverydevice 16 to deliver energy to metal matrix 40 to cause metal matrix 40to soften or flow (without delivering metal powder to the surface ofmetal matrix) (52) and control energy delivery device 16 and/or stage 18to move energy delivery device 16 relative to abrasive coating 22 suchthat energy is scanned across surface 40 of abrasive coating.

In this way, system 10 may be used to process abrasive coating 22 bydelivering additional metal matrix to abrasive coating 22 to furtherencapsulate previously deposited abrasive particles and by using energydelivery to soften or remelt metal matrix 40 after deposition ofabrasive coating 22 (in either order). The softening or melting of metalmatrix 40 may allow surface tension/surface energy to cause metal matrix40 to flow around abrasive particles 42 and make the height and surfaceroughness of abrasive coating 22 more uniform. This may reduce surfaceroughness of abrasive coating 22, improve incorporation of abrasiveparticles 44 in abrasive coating 22 such that abrasive particles 44 areless likely to be removed from abrasive coating 22 due to contact withan adjacent abradable coating, or both. Reduced surface roughness mayimprove a seal between a rotating component that includes multiplerotating elements and an adjacent stator or sealing component.

Abrasive coating 22 may be used as a coating on a substrate of arotating component, e.g., in a mechanical system, to protect thesubstrate from damage due to intentional or unintentional contact withan adjacent component, such as a stator. As described above, therotating component may include, for example, a pump rotor, a turbineblade, a compressor blade, a fan blade, a knife in a knife seal, or thelike. FIG. 6 is a conceptual diagram illustrating a system 70 thatincludes a rotating component 78, an abrasive coating 80 on rotatingcomponent 78, and a stationary component 76 adjacent rotating component78. In the example of FIG. 6 , system 70 is a gas turbine engine androtating component 78 is a rotating blade (e.g., a compressor blade or aturbine blade) of the gas turbine engine.

System 70 includes stationary component 76, which may be a blade trackor blade shroud. Abrasive coating 80 is on a tip or radially outersurface of rotating component 78, and is configured to impact anabradable coating 74 on stationary component 76 during at least someoperating conditions of system 70. Although a single rotating component78 is shown in system 70 for ease of description, in actual operation,system 70 may include a plurality of rotating components.

During operation of system 70, rotating component 78 rotates relative tostationary component 76 in a direction indicated by arrow 82. Ingeneral, the power and efficiency of system 70 can be increased byreducing the gap between stationary component 76 and rotating component78, e.g., to reduce or eliminate gas leakage around a tip of rotatingcomponent 78. Thus, system 70, in various examples, is configured toallow rotating component 78 to abrade into abradable coating 74 onstationary component 76 to define an abraded portion 84, which creates aseal between abradable coating 74 and rotating component 78. Theabrading action may create high thermal and shear stress forces atabrasive coating 80.

In some examples, the disclosure may be described by the followingclauses.

Clause 1. A method comprising: controlling, by a computing device, apowder source to deliver metal powder to a powder delivery device;controlling, by the computing device, the powder delivery device todeliver the metal powder to a surface of an abrasive coating; andcontrolling, by the computing device, an energy delivery device todeliver energy to at least one of the abrasive coating or the metalpowder to cause the metal powder to be joined to the abrasive coating.

Clause 2. The method of clause 1, wherein joining the metal powder tothe abrasive coating reduces an average surface roughness of theabrasive coating.

Clause 3. The method of clause 1 or 2, wherein the metal powder joinedto the abrasive coating further encapsulated at least some of theabrasive particles.

Clause 4. The method of any one of clauses 1 to 3, wherein the abrasivecoating comprises a metal matrix and abrasive particles at leastpartially encapsulated in the metal matrix.

Clause 5. The method of clause 4, wherein the metal powder comprises acomposition substantially similar to the metal matrix.

Clause 6. The method of clause 4 or 5, wherein the metal matrixcomprises a Ni- or Co-based alloy.

Clause 7. The method of any one of clauses 1 to 6, wherein the abrasiveparticles comprise at least one of a metal nitride, a metal carbide, ora metal oxide.

Clause 8. The method of any one of clauses 1 to 7, wherein the energydelivery device comprises a laser or a plasma source.

Clause 9. The method of any one of clauses 1 to 8, wherein the powderdelivery device comprises a blown powder deposition device.

Clause 10. A system comprising: a powder source; a powder deliverydevice; an energy delivery device; and a computing device, wherein thecomputing device is configured to: control the powder source to delivermetal powder to the powder delivery device; control the powder deliverydevice to deliver the metal powder to a surface of an abrasive coating;and control the energy delivery device to deliver energy to at least oneof the abrasive coating or the metal powder to cause the metal powder tobe joined to the abrasive coating.

Clause 11. The system of clause 10, wherein joining the metal powder tothe abrasive coating reduces an average surface roughness of theabrasive coating.

Clause 12. The system of clause 10 or 11, wherein the metal powderjoined to the abrasive coating further encapsulated at least some of theabrasive particles.

Clause 13. The system of any one of clauses 10 to 12, wherein theabrasive coating comprises a metal matrix and abrasive particles atleast partially encapsulated in the metal matrix.

Clause 14. The system of clause 13, wherein the metal powder comprises acomposition substantially similar to the metal matrix.

Clause 15. The system of clause 13 or 14, wherein the metal matrixcomprises a Ni- or Co-based alloy.

Clause 16. The system of any one of clauses 10 to 15, wherein theabrasive particles comprise at least one of a metal nitride, a metalcarbide, or a metal oxide.

Clause 17. The system of any one of clauses 10 to 16, wherein the energydelivery device comprises a laser.

Clause 18. The system of any one of clauses 10 to 17, wherein the powderdelivery device comprises a blown powder deposition device.

Clause 19. A computer-readable storage device comprising instructionsthat, when executed, configure one or more processors of a computingdevice to: control a powder source to deliver metal powder to a powderdelivery device; control the powder delivery device to deliver the metalpowder to a surface of an abrasive coating; and control an energydelivery device to deliver energy to at least one of the abrasivecoating or the metal powder to cause the metal powder to be joined tothe abrasive coating.

Clause 1. A method comprising: controlling, by a computing device, anenergy delivery device to deliver energy to an abrasive coating, whereinthe abrasive coating comprises a metal matrix and abrasive particles atleast partially encapsulated by the metal matrix; and controlling, bythe computing device, the energy delivery device to scan the energyacross a surface of the abrasive coating and form a series of softenedor melted portions of the metal matrix.

Clause 2. The method of clause 1, wherein the softened or meltedportions of the metal matrix allow the metal matrix to furtherencapsulate at least some of the abrasive particles.

Clause 3. The method of clause 1 or 2, wherein the softened or meltedportions of the metal matrix allow surface tension or surface energy tocause the softened or melted portions of the metal matrix to flowbetween abrasive particles.

Clause 4. The method of any one of clauses 1 to 3, wherein the methodreduces an average surface roughness of the abrasive coating.

Clause 5. The method of any one of clauses 1 to 4, wherein additionalmetal powder is not delivered to the metal matrix as the energy deliverydevice delivers energy to the abrasive coating.

Clause 6. The method of any one of clauses 1 to 5, wherein the metalmatrix comprises a Ni- or Co-based alloy.

Clause 7. The method of any one of clauses 1 to 6, wherein the abrasiveparticles comprise at least one of a metal nitride, a metal carbide, ora metal oxide.

Clause 8. The method of any one of clauses 1 to 7, wherein the energydelivery device comprises at least one of a laser or a plasma.

Clause 9. The method of any one of clauses 1 to 8, further comprising:controlling, by the computing device, a powder source to deliver metalpowder to a powder delivery device; controlling, by the computingdevice, the powder delivery device to deliver the metal powder to asurface of an abrasive coating; and controlling, by the computingdevice, the energy delivery device to deliver energy to at least one ofthe abrasive coating or the metal powder to cause the metal powder to bejoined to the abrasive coating.

Clause 10. A system comprising: an energy delivery device; and acomputing device, wherein the computing device is configured to: controlthe energy delivery device to deliver energy to an abrasive coating,wherein the abrasive coating comprises a metal matrix and abrasiveparticles at least partially encapsulated by the metal matrix; andcontrol the energy delivery device to scan the energy across a surfaceof the abrasive coating and form a series of softened or melted portionsof the metal matrix.

Clause 11. The system of clause 10, wherein the softened or meltedportions of the metal matrix allow the metal matrix to furtherencapsulate at least some of the abrasive particles.

Clause 12. The system of clause 10 or 11, wherein the softened or meltedportions of the metal matrix allow surface tension or surface energy tocause the softened or melted portions of the metal matrix to flowbetween abrasive particles.

Clause 13. The system of any one of clauses 10 to 12, wherein the methodreduces an average surface roughness of the abrasive coating.

Clause 14. The system of any one of clauses 10 to 13, wherein additionalmetal powder is not delivered to the metal matrix as the energy deliverydevice delivers energy to the abrasive coating.

Clause 15. The system of any one of clauses 10 to 14, wherein the metalmatrix comprises a Ni- or Co-based alloy.

Clause 16. The system of any one of clauses 10 to 15, wherein theabrasive particles comprise at least one of a metal nitride, a metalcarbide, or a metal oxide.

Clause 17. The system of any one of clauses 10 to 16, wherein the energydelivery device comprises at least one of a laser or a plasma.

Clause 18. The system of any one of clauses 10 to 17, furthercomprising: a powder source; and a powder delivery device, wherein thecomputing device is further configured to: control the powder source todeliver metal powder to the powder delivery device; control the powderdelivery device to deliver the metal powder to a surface of an abrasivecoating; and control the energy delivery device to deliver energy to atleast one of the abrasive coating or the metal powder to cause the metalpowder to be joined to the abrasive coating.

Clause 19. A computer-readable storage device comprising instructionsthat, when executed, configure one or more processors of a computingdevice to: control an energy delivery device to deliver energy to anabrasive coating, wherein the abrasive coating comprises a metal matrixand abrasive particles at least partially encapsulated by the metalmatrix; and control the energy delivery device to scan the energy acrossa surface of the abrasive coating and form a series of softened ormelted portions of the metal matrix.

Clause 20. The computer-readable storage device of clause 19, furthercomprising instructions that configure one or more processors of thecomputing device to: control a powder source to deliver metal powder toa powder delivery device; control the powder delivery device to deliverthe metal powder to a surface of an abrasive coating; and control anenergy delivery device to deliver energy to at least one of the abrasivecoating or the metal powder to cause the metal powder to be joined tothe abrasive coating.

The techniques described in this disclosure may be implemented, at leastin part, in hardware, software, firmware, or any combination thereof.For example, various aspects of the described techniques may beimplemented within one or more processors, including one or moremicroprocessors, digital signal processors (DSPs), application specificintegrated circuits (ASICs), field programmable gate arrays (FPGAs), orany other equivalent integrated or discrete logic circuitry, as well asany combinations of such components. The term “processor” or “processingcircuitry” may generally refer to any of the foregoing logic circuitry,alone or in combination with other logic circuitry, or any otherequivalent circuitry. A control unit including hardware may also performone or more of the techniques of this disclosure.

Such hardware, software, and firmware may be implemented within the samedevice or within separate devices to support the various techniquesdescribed in this disclosure. In addition, any of the described units,modules or components may be implemented together or separately asdiscrete but interoperable logic devices. Depiction of differentfeatures as modules or units is intended to highlight differentfunctional aspects and does not necessarily imply that such modules orunits must be realized by separate hardware, firmware, or softwarecomponents. Rather, functionality associated with one or more modules orunits may be performed by separate hardware, firmware, or softwarecomponents, or integrated within common or separate hardware, firmware,or software components.

The techniques described in this disclosure may also be embodied orencoded in an article of manufacture including a computer-readablestorage medium encoded with instructions. Instructions embedded orencoded in an article of manufacture including a computer-readablestorage medium encoded, may cause one or more programmable processors,or other processors, to implement one or more of the techniquesdescribed herein, such as when instructions included or encoded in thecomputer-readable storage medium are executed by the one or moreprocessors. Computer readable storage media may include random accessmemory (RAM), read only memory (ROM), programmable read only memory(PROM), erasable programmable read only memory (EPROM), electronicallyerasable programmable read only memory (EEPROM), flash memory, a harddisk, a compact disc ROM (CD-ROM), a floppy disk, a cassette, magneticmedia, optical media, or other computer readable media. In someexamples, an article of manufacture may include one or morecomputer-readable storage media.

In some examples, a computer-readable storage medium may include anon-transitory medium. The term “non-transitory” may indicate that thestorage medium is not embodied in a carrier wave or a propagated signal.In certain examples, a non-transitory storage medium may store data thatcan, over time, change (e.g., in RAM or cache).

Various examples have been described. These and other examples arewithin the scope of the following claims.

What is claimed is:
 1. A system comprising: an energy delivery device;and a computing device, wherein the computing device is configured to:control the energy delivery device to deliver energy to an abrasivecoating, wherein the abrasive coating comprises a metal matrix andabrasive particles at least partially encapsulated by the metal matrix;and control the energy delivery device to scan the energy across asurface of the abrasive coating and form a series of softened or meltedportions of the metal matrix.
 2. The system of claim 1, wherein thesoftened or melted portions of the metal matrix allow the metal matrixto further encapsulate at least some of the abrasive particles.
 3. Thesystem of claim 1, wherein the softened or melted portions of the metalmatrix allow surface tension or surface energy to cause the softened ormelted portions of the metal matrix to flow between abrasive particles.4. The system of claim 1, wherein the method reduces an average surfaceroughness of the abrasive coating.
 5. The system of claim 1, whereinadditional metal powder is not delivered to the metal matrix as theenergy delivery device delivers energy to the abrasive coating.
 6. Thesystem of claim 1, wherein the metal matrix comprises a Ni- or Co-basedalloy.
 7. The system of claim 1, wherein the abrasive particles compriseat least one of a metal nitride, a metal carbide, or a metal oxide. 8.The system of claim 1, wherein the energy delivery device comprises atleast one of a laser or a plasma.
 9. The system claim 1, furthercomprising: a powder source; and a powder delivery device, wherein thecomputing device is further configured to: control the powder source todeliver metal powder to the powder delivery device; control the powderdelivery device to deliver the metal powder to a surface of an abrasivecoating; and control the energy delivery device to deliver energy to atleast one of the abrasive coating or the metal powder to cause the metalpowder to be joined to the abrasive coating.
 10. A system comprising: anenergy delivery device; and a computing device, wherein the computingdevice is configured to: control the energy delivery device to deliverenergy to an abrasive coating after deposition of the abrasive coating,wherein the abrasive coating comprises a metal matrix and abrasiveparticles at least partially encapsulated by the metal matrix; andcontrol the energy delivery device to scan the energy across a surfaceof the abrasive coating to re-melt of reflow the metal matrix.